The present invention relates to blade assemblies for electric hair clippers, and specifically to the construction and arrangement of blades in such assemblies.
Conventionally available electric clippers include two main components: a combined handle and drive system, and a blade assembly which is frequently removable. The blade assembly includes a housing enclosing a fixed blade and a moving blade reciprocating relative to the fixed blade. In some applications, the blade assembly is intended to be disposable, such as when used in clipping patients' hair prior to surgery. Also included in the blade assembly is a cam follower or similar device generally disposed in the housing and configured for engagement with a drive member in the handle portion, which transmits the driving motion generated by the drive member to the moving blade.
Conventional blade assemblies also include a spring or other biasing structure for biasing the moving blade against the fixed blade. Hair cutting takes place through the scissors action of the reciprocating action of the moving blade relative to the fixed blade.
One common disadvantage of conventional clippers occurs through the separate construction of the fixed and moving blades. This occurs largely due to the fact that the construction of the tooth pattern and geometry of the fixed blade is often distinct from those of the moving blade. More specifically, the spacing, tip shape and angle of the teeth often vary between the fixed and moving blades. The presence of multiple blade parts adds to the burden on clipper manufacturers of maintaining inventory and keeping assembly workers supplied with parts on a timely basis. In addition, a greater disparity of component parts often results in a correspondingly more difficult assembly worker training task for the manufacturer.
A further disadvantage of the conventional system of employing separate parts for the fixed and moving blades is that these blades are often produced one-at-a-time in progressive die tooling by stamping machines from rolled steel stock. The high cost of modifying or replacing existing stamping dies has tended to discourage change in this area.
Thus, an object of the present invention is to provide improved fixed and stationary blade elements for use in a clipper blade assembly wherein the fixed and moving blades are provided as a substantially identical single unit which can either be used as a fixed blade or a moving blade.
Another object of the present invention is to incorporate specific geometry of fixed and moving blades into a single blade part so that the desired cutting action and blade orientation of conventional clippers is maintained.
Still another object of the present invention is to provide a blade assembly for use in an electric clipper wherein the fixed and stationary blades are made of substantially identical parts.